Trigger Point Injection Defined

Trigger points are focal areas of spasm and inflammation in skeletal muscle. The rhomboid and trapezius back muscles, located in the upper back and shoulder areas, are a common site of trigger points.

In addition to the upper spine, trigger points can also occur in the low back or less commonly in the extremities.

Often there is a palpable nodule in the muscle where the trigger point is located. The area is tender, and frequently when pushed, pain radiates from the trigger point itself to an area around the trigger point.

They may also occur with tension headache and temporomandibular pain. Acute trauma or repetitive minor injury can lead to the development of trigger points.

How is the trigger point injection procedure performed?

The trigger point injection is performed in the health-care professional’s office, usually with the patient either lying on the exam table on the stomach or sitting on the exam table.

The exact protocol varies. The health-care professional performing the procedure locates the trigger point by manual palpation and marks the site.

Ultrasound guidance is not generally necessary. The injection site is then cleaned. Alcohol or another skin cleanser such as betadine is commonly used to clean the injection site.

Frequently, a numbing spray such as ethyl chloride is used to anesthetize the skin and make the actual injection less painful.

The needle is then inserted into the trigger point and the medication is injected. After the injection, a simple adhesive bandage may be applied.

If the area is painful after the injection, ice, heat, acetaminophen (Tylenol), or over-the-counter nonsteroidal anti-inflammatory medications such as ibuprofen (Advil) or naproxen sodium may be used.

When is a trigger point injection used?

Trigger point injection is used when a patient has a painful trigger point, especially when pain radiates from the trigger point to the surrounding area.

Trigger point injections may be used as a treatment for conditions such as fibromyalgia and myofascial pain syndrome. However, the trigger points commonly recur with chronic pain syndromes.

What are complications and side effects of trigger point injections?

A potential complication from the trigger point injection procedure is post-injection pain. This is relatively uncommon, but it can occur.

This pain usually resolves by itself after a few days. It is more common when no medication is injected into the trigger point (dry needling).

Ice, heat, or over-the-counter medications such as acetaminophen, ibuprofen, or naproxen sodium may be useful for post-injection pain.

If a steroid medication is injected into the trigger point, shrinkage of the fat under the skin can occur, leaving a dent in the skin.

This does not occur when only anesthetic is injected without any steroid medication. Other side effects are rare with trigger point injections but can occur anytime a needle punctures the skin, including infection and bleeding.

How frequently do trigger point injections need to be administered?

Optimally, a trigger point resolves after one injection. This may happen when a patient has one isolated trigger point, especially if the cause of the trigger point has been removed (such as a trigger point caused by a repetitive minor trauma or movement that will no longer be performed).

Trigger points caused by chronic conditions such as fibromyalgia and myofascial pain syndrome tend to recur due the underlying problem.

In these cases, trigger point injections may be administered on a regular or as needed basis. The frequency of trigger point injections depends on the medication being injected.

If only lidocaine or a mixture of anesthetics is injected, then the injections can be administered as ongoing therapy as frequently as monthly.

If a steroid medication is injected, TPIs should be administered much less frequently, at the discretion of the treating health-care professional, because of the risk of tissue damage or shrinkage from the steroid medication.

What do trigger points have to do with back pain and how are they treated?

Trigger points are tight-tender areas of muscle that can be very painful to touch and can cause referred, radiating pain.

Activation of trigger points in the paraspinal muscles can be caused by sudden overload during lifting objects, twisting and flexing the back, stooping or poor posture. You may also have tightness in your back that prevents you from some movements.

Trigger points can be very painful and disabling and may even cause weakness. Proper diagnosis and treatment is essential.

Trigger Point therapy is part of the multidisciplinary treatments we recommend and prescribe.

A thorough history and physical exam focusing on the symptoms of neck and back pain can help reveal the underlying cause of the pain.

Many patients will have trigger points that can contribute to all or most of their pain. Trigger point injection therapy is usually helpful with these patients and helps them get back on the road to recovery.

The injection is usually performed with a mixture of lidocaine and bupivicaine to ease some of the stress from injecting the muscle, followed by some dry needling which is thought to de-activate the point.

A technique called Myofascial release can be performed after the injection for further relaxation of the affected muscles. A technique called Spray-and-stretch can also be used instead of injections.

Trigger point therapy may need to be repeated for multiple sessions 1-2 weeks apart until the points are de-activated and the patient is more mobile with a decreased level of pain and tenderness.

It is one step in the road to recovery from neck and back injury and works well combined with physical/massage therapy and/or manipulative treatments.